Air conditioning systems generally have provided an overall controlled climate within a building or on various floors in a building by providing conditioned air to an area and withdrawing air from the area for return to an air conditioning unit. Fresh air is introduced under controlled conditions as part of the conditioned air.
With the advent of computers, very sophisticated computer controlled systems are now possible and particularly in large, high rise buildings.
However, the sophistication of the system and the attempt at uniform control often detracts from the comfort of the individuals on the various floors of a building and within zones or areas on those floors. It is now acknowledged that few people perceive the effectiveness of an air conditioning system the same, some preferring a cooler environment in which to work, others a slightly warmer climate.
Accordingly, there is a desire to improve the general acceptance of air conditioning systems by evolving a system which offers many occupants of a zone a measure or degree of individual control over the movement of conditioned air in that zone.
There is commercially available a system by Hydro Therm under the trade mark SPACE PAK.TM. which is often used to provide central air conditioning for older homes or small buildings, particularly those which do not have forced air heating systems. The SPACE PAK.TM. system locates a blower coil unit in the attic, for example, and provides an insulated plenum in communication with the blower coil unit and from which plenum flexible pre-insulated tubing extends to each room of the house. The flexible tubing may be threaded from floor to floor through closets, between wall studs, or between floor or ceiling joists. Constant volume conditioned air is delivered to air outlets installed in each room of the house in the ceiling, walls or floors.
With houses and small buildings, the SPACE PAK.TM. system is relatively small and individual control of the air distribution is not considered necessary or desirable as a cost effective system.
Canadian patent No. 1,071,005 of Schmidt et al granted Feb. 3, 1980, relates to a method and apparatus for ventilation or air conditioning occupied rooms and more particularly to a system providing within an occupied room, small zones where thermal conditions are individually adjusted in such fashion that the motion of air may be regulated. This is over and above general room temperature control. The Schmidt et al system provides a primary air climate control system with low velocity air as well as a secondary system, the secondary system providing individual manually controlled adjustable air outlets. These outlets, as part of the secondary system, provide in each of the constantly occupied spaces a "local" climate zone which is distinct from the basic primary climate control conditions. Schmidt et al provides adjustable nozzles at the ends of riser tubes or stanchions to provide the supplemental secondary air to individual work stations or local zones.
The Schmidt et al system has not proven satisfactory in that the only control of supplemental air flow is manual adjustment of nozzles on riser tubes or stanchions. The riser tubes or stanchions are unsightly and can interfere with movement of furniture and people within the areas or zones.
Accordingly there is a need to provide a system which permits a degree of individual control of the flow of air at various locations within particular areas and zones and which will provide at least a perception of cooler conditions within the area or zone due to the movement of air directed to that area or zone.